The developing and fixing of an x-ray film, like most photographic film, usually involves the use of separate developing, fixing and rinsing baths. The preparation of such baths can be time consuming, can be somewhat of a nuisance, and can result in poor images because of, for example, too little or too much contact between the film and developing solution or between the film and fixing solution. More importantly, the practicing physician or dentist, while needing the developed film as quickly as possible, is forced to send the film out for processing or to maintain a developing studio in which he can carry out film developing -- a task for which he is ill-prepared in terms of time and training.
In my U.S. Pat. No. 3,682,638 issued Aug. 8, 1972, I disclosed a radiosensitive film which comprises (a) a support, (b) an acidic gelatin-silver halide emulsion layer having a fixer dispersed therein and (c) an alkaline layer comprising a developer. The latter film can be developed and fixed by merely immersing it in running water at a temperature in the range of about 110.degree.- 125.degree.F., for example. Although the latter film represents a significant advance in the art, continued improvement is desired in avoiding premature reaction between fixing agents and the unexposed silver halide.
Other workers in the art have also suggested ways of simplifying film development. For example, Tregillus et al, in U.S. Pat. No. 3,179,517 and Yutzy et al, in U.S. Pat. No. 3,260,598 suggest developing a film by contacting the exposed film with a web which contains the developer and fixer. Yudelson et al, in U.S. Pat. No. 3,212,896 suggest a film where a layer thereof includes both developers and fixers in heat sensitive capsules. In the latter case the exposed film is heated to release the active agents from the capsules.
It is an object of the present invention to provide a novel x-ray film which is simpler in structure than the films of the prior art, which is easier to develop, and which contains both developing and fixing agents in the same layer, and separate from the silver halides, in a manner such that the film is capable of producing a permanent negative by a novel one-step developing and fixing process and in a manner to avoid premature reaction between the fixing agents and the silver halides.